Selective catalytic reduction urea air premixing jet system

Abstract

The invention relates to a selective catalytic reduction urea air premixing jet system, which belongs to the technical field of diesel engines. The selective catalytic reduction urea air premixing jet system comprises a controller, a metering pump, a urea solution tank, a urea solution pressure-stabilizing cavity, a reflux valve, a jet electromagnetic valve, an air atomizing nozzle, an air electromagnetic valve, an air pressure-stabilizing cavity, an air pressure-reducing valve, a compressed air tank, a cooling liquid electromagnetic valve, an integrated heat exchange device, a pipeline heat exchange device and a urea solution tank heat exchange device. The selective catalytic reduction urea air premixing jet system has the characteristics of low energy consumption, high accuracy and stability, simple structure, low system development cost and manufacturing cost and capacity of effectively reducing fuel oil consumption and NOx emission of the diesel engines.

Description

technical field [0001] The invention relates to a device in the technical field of diesel engines, in particular to a selective catalytic reduction urea air premixing injection system based on the purification of NOx emissions from diesel engines. Background technique [0002] Nitrogen oxides NOx is one of the main harmful exhaust emissions of diesel engines, which can be purified by in-engine NOx or out-of-engine NOx. Since the purification of NOx inside the engine generally leads to an increase in the fuel consumption rate of the diesel engine and an increase in the emission of particulate matter PM, while the purification of NOx outside the engine is beneficial to the reduction of the fuel consumption rate of the diesel engine and the reduction of PM emissions, thereby reducing the greenhouse gas carbon dioxide CO 2 Therefore, the use of off-machine purification technology for NOx is more in line with the requirements of energy saving and environmental protection. Among ...

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Problems solved by technology

Its shortcomings are: the electronically controlled nozzle is installed on the exhaust pipe, and a heat insulation and vibration reduction device needs to be added; the urea solution is heated by the high-temperature exhaust gas of the diesel engine, and the heat resistance of the heating device is high; the urea solution heated by the exhaust gas Located at the nozzle, it cannot effectively solve the problem of low-temperature crystallization of urea solution in other parts of the system, and it is easy to cause the temperature of the urea solution to be too high locally, resulting in its deterioration. In order to realize the circulation of the heated urea solution in the system, more energy will be consumed. energy and increase the burden on the urea solution delivery pump; from the description of the patent, the system also includes a liquid cooling subsystem, which further complicates the system and makes it difficult to optimize the technical economy

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